Pneumatic tires in particular suffer damage in the form of tears or holes when they run over sharp objects, the result being loss of air pressure within the tire. Sealants are known for providing a seal as reliable as possible of this type of damage, at least temporarily, that is, for a certain period, until the pneumatic tire can be replaced. These sealants are introduced into the tire, for example, with the aid of a device using a pressure source and a sealant, after unscrewing the valve insert, or directly via the valve.
Sealants of this type are well known from the related art, and mention is made here of the following European patent publications by way of example: EP 0 988 960 B1, U.S. Pat. No. 6,992,119, U.S. Pat. No. 6,063,837; EP 0 584 597 B1; and, German patent publication DE 197 53 630 B4.
EP 0 988 960, DE 197 53 630 and U.S. Pat. No. 6,992,119 disclose sealants based on rubber latex. In these publications, non-deproteinated natural rubber latex is used and dispersing and emulsifying agents are optionally admixed with the sealant. In the sealant based on non-deproteinated natural rubber latex, it is not possible for the dispersing or emulsifying agents to develop their full effect, so that there are therefore only limited possibilities for improving the temperature stability at elevated temperatures, and improvement of susceptibility to coagulation. The presence of proteins in the natural rubber latex moreover causes an increased allergenicity potential.
U.S. Pat. No. 6,063,837 and EP 0 584 597 disclose deproteinated sealants based on natural rubber latex. Here again, dispersing or emulsifying agents are optionally admixed with the sealant. The use of natural rubber latex that has been previously deproteinated improves the temperature stability at elevated temperatures, and improves susceptibility to coagulation, while at the same time reducing allergenicity potential. The deproteinated natural rubber latex here is produced in a separate, complex, multistage process starting from non-deproteinated natural rubber latex. However, in this process it is not possible to remove completely the proteins within the natural rubber latex, and although the allergenic potential can be reduced, it cannot be eliminated.
It is also known that synthetic latices can be used for means of temporary sealing inflatable articles. However, it has been found that these means generally exhibit poorer sealing action than those based on natural rubber latex.